New developments at the for Metal Forming and Metal Forming Machine Tools show that magnesium sheets possess excellent forming behavior, if the process is conducted at elevated temperatures. For the evaluation of mechanical properties relevant for forming of magnesium sheets, uni axial tensile tests have been carried out at various temperatures and strain rates.

Deep drawing tests with magnesium alloys AZ31B, AZ61B, and M1 show very good formability in a temperature range between 200 and

2508C. Besides temperature, the influence of forming speed on limit drawing ratio has been investigated. The obtained results lead to the conclusion that it is possible to substitute conventional aluminum and steel sheets by using magnesium sheet metal wrought alloys.

1. Introduction

In order to reduce fuel consumption, general efforts have been made to decrease the weight of automobile constructions by an increased use of lightweight materials. In this framework, magnesium alloys are of special interest because of their low density of 1.74 g/cm3.

Presently, magnesium alloys for the use as automobile parts are mainly processed by die casting. The die casting technology allows the manufacturing of parts with complex geometry. However, the mechanical properties of these parts often do not meet the requirements concerning the mechanical properties (e.g. endurance strength and ductility). A promising alternative has to be seen in components that are manufactured by forming processes. The parts manufactured by this technology are characterized by advantageous mechanical properties and fine-grained microstructure without pores [1]. However, a widespread use of forming technologies for the processing of magnesium alloys is restricted because of insufficient knowledge about the forming technologies and suitable process parameters that have to be applied [2,3].

Automotive body constructions offer a great potential for the application of magnesium sheet metal components.

In general, the automotive body completely consists of sheet metal parts and represents a share of about 25% of the entire vehicle mass. Therefore, the substitution of conventional sheet materials by magnesium sheets would lead to essential weight savings in this application.

2. Plastic material properties of magnesium sheets

Magnesium alloys show a limited formability at room temperature. This results from the fact that the hexagonal crystal structure and the low tendency to twinning only allow limited deformations. The differently orientated crystallites only show a deformation on the individual base slip plane, which leads to a mutual slip hindrance [4, 5]. A considerable improvement of the forming qualities can be achieved by applying temperature. The considerable increase in formability that occurs in the temperature range from 200 to2258C (depending on alloying composition) was investigated